870 magazine spring question?

[Gary O]

I just purchased an 870 Tactical Synthetic 12 gauge with 7 shot capacity. This morning I was loading it to the top for home defense and as the magazine spring became more compressed, it occurred to me that these factory springs might take a "set" after setting ready to go for a long period of time. What say you? Is there an aftermarket spring worth buying? Thanks...

[awiner]

Current magazine springs (both shotgun and handgun) are made to withstand being under compression without much loss of compression over time.

What wears these springs is loading (compressing) them and unloading (uncompressing) them.

Staying loaded will not significantly reduce the effectiveness. With that said, springs are cheap and its a good idea to replace them every so many years.

I like Wolff XP (Extra Power) springs.

[Bobby Ricigliano]

I just purchased an 870 Tactical Synthetic 12 gauge with 7 shot capacity. This morning I was loading it to the top for home defense and as the magazine spring became more compressed, it occurred to me that these factory springs might take a "set" after setting ready to go for a long period of time. What say you? Is there an aftermarket spring worth buying? Thanks...

Have you taken it out and shot it yet? I wouldn't recommend buying a weapon and just loading it up and putting it away. (Your post implies that) Even if you are an expert with 870's, it should still be test fired at a minimum. Even brand new guns are fubar sometimes.

The spring will be fine, but it is possible for the shells to deform over time. I habitually unload and inspect the shells in my HD shotguns from time to time. If they are ragged looking I throw them in my range bag.

I changed the springs on a couple shotguns recently, but the springs were 30+ years old.

[Bobby Ricigliano]

What wears these springs is loading (compressing) them and unloading (uncompressing) them.
(Extra Power) springs.

This is true, but the shells themselves can deform and thus do need to be unloaded and inspected occasionally.

[awiner]

This is true, but the shells themselves can deform and thus do need to be unloaded and inspected occasionally.

Good point. I only answered about the spring but shell deformation is something that needs to be inspected routinely as well.

[bernieb90]

Current magazine springs (both shotgun and handgun) are made to withstand being under compression without much loss of compression over time.

What wears these springs is loading (compressing) them and unloading (uncompressing) them.

Staying loaded will not significantly reduce the effectiveness. With that said, springs are cheap and its a good idea to replace them every so many years.

I like Wolff XP (Extra Power) springs.

This is actually a common misconception.

"Relaxation of springs is a function of a fairly high stress (but usually lower that required to cause set) over a period of time. A spring held at a certain stress will actually relax more in a given time than a spring cycled between that stress and a lower stress. The reason is that it spends more time at the high stress."

http://www.rockfordspring.com/relaxationofsprings.asp

Springs that are cycled repeatedly typically fail by breaking due to fatigue. We see this most often in firearms in some of the smaller springs like trigger return springs in high round count (heavily dry fired) Glocks.

All that being said the magazine spring in a shotgun is much stronger than needed for the job that it does. Even if the spring does loose a small percentage of it's original force over a long period it will still be strong enough to feed shells.

My dad's 25+ year old Mossberg 500 was quite heavy used, and I did decide to replace the spring with a Wolff XP.



As you can see the upgraded spring was not only longer, but was much stiffer than the original. I expect it to last many years loaded before it needs to be replaced.

[aippi]

Very good post Bernie. The Rockford Spring Info was great, thanks. This topic is beat to death on the net and seldom does information enter from the experts in the field like a company that builds springs.

As for a spring lossing any of it's function. The weapon that I may have to use to defend my life with will be at 100% operating condition at all times. Not 95% not even 99%. Replacing a $4 mag tube spring once a year is a no brainer when my life could be on the line. This gets lost in the debate when we are addressing defense guns. I am amazed that the topic is even debated.